1. Field of the Invention
This invention relates to a locking arrangement for a switchgear cabinet, having a holding device, which contains a manual lever in a handle receptacle, wherein the manual lever can be arrested in a locked position on the holding device by a displaceably seated bolt and for actuating the bolt, the holding device, which is in operative contact with the bolt, contains a lock in a lock housing.
2. Description of Related Art
A locking arrangement of this type is known from German Patent Reference DE 198 01 721 C1. The manual lever of this locking arrangement is pivotally fastened in a holding device. Here, the manual lever can be pivoted in a plane extending perpendicular with respect to the cabinet door to which the holding device is attached. In the initial position the manual lever is maintained in a lever receptacle. A bolt prevents the manual lever from being inadvertently moved into the open position. The bolt can be disengaged by a slide. The slide is actuated by a lock, for example a profiled semi-cylinder. As soon as the manual lever is disengaged, it can be grasped and pivoted into its open position.
A similar arrangement is also known from European Patent Reference EP 0 155 543 B1. There, the manual lever is also securely fixed in a handle receptacle. As soon as it is disengaged, it is snapped into an actuating position through the action of a spring element. It can be grasped there and pivoted around an axis of rotation extending perpendicular with respect to the cabinet door.
One object of this invention is to provide a locking arrangement of the type mentioned above but which allows an arbitrary, but definitely selected group of people access to a switchgear cabinet, and wherein a later change of the lock system is easily possible.
This object is achieved with a lock, hereinafter called secondary lock, designed as a number lock with adjustable number wheels. The secondary lock is inserted into a lock receptacle in the lock housing and is interchangeably fastened from the inside of the lock housing in fastening receivers. The secondary lock has a control member acting on an actuating shoulder of the actuating member, but is not connected.
The number lock has coding, which initially is only known to the owner of the switchgear cabinet. The owner can make the code numbers available to a desired group of people, for example operators and maintenance personnel. If a change of the lock becomes necessary after a time, for example because the requirements for use change, the secondary lock can be removed without problems. The cost required for this is rather small, because the secondary lock merely needs to be removed from the fastening receivers.
In accordance with one preferred embodiment of this invention, the secondary lock has a rotary slide which supports the control member arranged in the interior of the lock housing. The rotary slide is not blocked when the code is set at the number wheels, but is blocked at other times. The secondary lock has a decoding device, which can be actuated when the number code is set, and a new number code can be set on the number wheels when the decoding device is actuated.
Thus the owner of the switchgear cabinet can change the coding when the group of users changes.
Possible unauthorized operation of the secondary lock are limited, if the lock receptacle for the lock housing widens toward the exterior surface of the lock in the form of a shoulder, and the shoulder receives a flange of the secondary lock flush with the surface.
In one embodiment of this invention, the secondary lock has a resting surface facing the interior of the lock housing, which is supported on a support element of the lock housing. The fastening receiver is embodied as at least one screw receiver formed in one piece on the lock housing. Fastening screws are inserted into the fastening receiver and screwed into the secondary lock. The fastening screws maintain the contact surface clamped to the support element. A secure fixation of the secondary lock is thus achieved, which can also simply be reversed when required.
A locking arrangement in accordance with this invention can be designed so that in place of the secondary lock a cover is fastened on the inside of the lock housing. The cover then masks the lock receptacle. In this way the locking arrangement can be adapted to the requirements of the user. If no use of a secondary lock is intended, the cover is inserted. It then can no longer be removed from the outside, because it is fixed in place on the inside of the lock housing.
The ability to exchange the secondary lock is possible in a particularly simple manner if the actuating member has a push rod, which is displaceably seated in the lock housing. The push rod has an actuating shoulder projecting in the direction of the secondary lock. The actuating shoulder has a control cam, on which the control member of the secondary lock runs up when the actuating member is operated. Thus there is no fixed mechanical association between the fastening shoulder and the control member, which would have to be released in the event of an exchange.
In accordance with a preferred embodiment of this invention, the lock housing receives a lock in addition to the secondary lock, which is also in operative contact with the bolt. With the lock mechanism thus created, it is possible to operate the bolt with two locks, which operate independently of each other. Two different groups of authorized users can thus be defined, each of which then has access to the locking arrangement.
The ability to exchange the secondary lock becomes possible in a simple way if the lock has a control member which is in loose engagement with an actuating shoulder of the control member for operating the bolt.